Hinged rings of the prior art, having hinges on both sides of the shank, each have disadvantages of ease of use and practicability.
Ross, U.S. Pat. No. 4,592,211, describes a ring hinged on each side which may be pulled open to a single larger position. One side of the ring may be pulled out until a stop is reached. The ring can then be pushed into the closed position for wear. The ring is not intended for wearing in the opened position, but is intended to pass easily over an enlarged finger joint, and then be closed for wear.
Newman, U.S. Pat. No. 3,890,801, describes an opening ring which can be worn in an open or closed position. Ends of an inserted section engage frictionally inside the hollow shank portions of the ring. The ring cannot be fixed in any of the open positions and thus, if the frictional engagement becomes loose in wear, the ring may open to a larger size, inadvertently, and be lost.
Manne, U.S. Pat. No. 3,423,956, describes another ring having two hinged portions. The hinged portions include springs which bias the shank sections toward each other into a normal position where the sizing section establishes a minimum ring size. In a second embodiment, the springs at the hinges are eliminated and the insert member is fabricated of a springy metal. During movement relative to the surrounding member, the insert member is flexed so as to exert a spring bias against outward movement, preventing inadvertent expansion of the ring. This ring also cannot be set to a fixed size open position.
Kelrick, U.S. Pat. No. 3,736,770, describes an adjustable ring having hinged shank portions on each side and a latch piece secured to one of the portions having a tooth for engaging an aperture in a separate spring. The inner ends of the latch and spring are telescopically received in the second pivoted section and the inner end of the spring is fastened thereto by a pin. The latch may not be easy to manipulate. This patent is asserted to be an improvement over Newman, U.S. Pat. No. 3,221,514.